I need to replace the 4.2L engine in my '88 wrangler and I was wondering if I could drop in an older 4.2L engine. I found a '78 4.2L, but I don't think they're interchangable. Does anyone have personal experience with this, or any advice?
Thanks,
Josh
The main difference is the pilot bearing in the flywheel center. The 78 has a bushing that is slightly larger then the bearing the 88 uses.
You can just use the 88's flywheel as far as I know or you can pull out the bushing and the bushing retainer and press a bearing in I think.
Other than that, the 78 might have a 1 bbl carb and manifold on it. You can swap over the 88's 2 bbl easy enough. If it already has the 2 bbl, you would be laughing. That old one is the better carb. In either case, a kit for the carb is only twenty bucks or so.
The 88 has better engine mounts, I would keep them or their style mount
Just FYI, if your 88 is only blowing oil into the air filter, (blowby), that can be fixed usually. It is usually a bad line on the PCV valve or a dead charcoal canister. A new engine will do the same....
Oh, I have a 78 engine in my 86 I think also.
You also 'can' hook all the pollution junk up to the 78 too if you want....
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail >Oops, the bushing and bearing are in the end of the crank and will need to be switched. A local machine shop had a slick tool for pulling them out.
Mike
Mike Roma>
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